A novel peptide-based fluorescence chemosensor for selective imaging of hydrogen sulfide both in living cells and zebrafish

Abstract

Hydrogen sulfide (H2S) plays an important role as a signaling compound (gasotransmitter) in living systems. However, the development of an efficient imaging chemosensor of H2S in live animals is a challenging field for chemists. Herein, a novel peptide-based fluorescence chemosensor L-Cu was designed and synthesized on the basis of the copper chelating with the peptide ligand (FITC–Ahx–Ser–Pro–Gly–His–NH2, L), and its H2S sensing ability has been evaluated both in living cells and zebrafish. The peptide backbone and Cu2+-removal sensing mechanism are used to deliver rapid response time, high sensitivity, and good biocompatibility. After a fast fluorescence quench by Cu2+ coordinated with L, the fluorescence of L is recovered by adding S2− to form insoluble copper sulfide in aqueous solution with a detection limit for hydrogen sulfide measured to be 31nM. Furthermore, the fluorescence chemosensor L-Cu showed excellent cell permeation and low biotoxicity to realize the intracellular biosensing, L-Cu has also been applied to image hydrogen sulfide in live zebrafish larvae. We expect that this peptide-based fluorescence chemosensor L-Cu can be used to study H2S-related chemical biology in physiological and pathological events.